Screw it, I'll respond to the OP - RAID1 is a form of backup. Now, before an unholy shitstorm is whipped up in response to the heresy I've uttered, consider this:
The form that a backup takes should depend on the concerns of the person who owns the data.
Disclaimer: I wouldn't ever recommend to a business customer that all they need to protect their data adequately is RAID1. The simple fact is that while RAID1 provides a pretty good assurance that if one disk fails, their data is still on the other disk. From that point of view, it is a backup. "Backup" is not a word that was invented with regard to data, so please don't talk as if you can define the term.
However, there are more data loss possibilities that ought to be considered.
Not an comprehensive list, just off the top of my head:
* Fire (or some natural element, say a flood) destroys the computer
* Someone with malicious intent deletes the data
* Someone steals the computer
* Malware messes with the data in some way
* Data corruption not necessarily caused by hardware
* Someone is actually out to destroy every last trace of that data, targetting backups as well
Many/most of these may not be (or not ought to be) concerns of the person owning the data. The owner, once they have a reasonable grasp of the threats to their data should decide based on what's available, the advantages and disadvantages of that form of backup, and their budget.
Someone might write down the important bits of data or print them, which if that was all they needed would be a decent form of backup, unless water damage was a possibility they considered and left the written/printed backup on top of the computer that hosts the original copy of the data.
It's a good point what someone said about simply storing the data (only) on an external HDD is not a backup. I point out to customers that the technology in that device is almost identical to the technology in their computer, and it's even more vulnerable to damage because it's a more portable item. I'm a bit surprised that the point needs to be made on a semi-technical forum though.
I just think that some people get this 'holier than thou' impression and think that they speak the truth. I remember in another thread (whether it was on this forum or not, I can't remember) someone got carried away with this idea and said "RAID0 isn't even RAID!" (presumably because that person had the idea that RAID = protecting data), to which someone responded "err, yes it is".
Facebook
Twitter